Easy Backset MarkerNo. EBM-234The Easy Backset Marker marks backset location for 2-3/4" and 2-3/8" backset.It includes edge bore marks for 1-3/4" doors and is quick and easy to use! Installing locksets and deadbolts is an everyday occurrence. This tool makes it easy to accurately mark the backset on the door when a jig is not available.